A 69-year-old woman was admitted because of unconsciousness and multiple cranial neuropathy. She had suffered diarrhea 2 weeks previously. On examination, she was noted to have total external and internal ophthalmoplegia, bilateral facial palsy, dysphagia, dysarthria, neck weakness, distal motor weakness of all limbs, and ataxia. She had also presented with hyporeflexia and hypoesthesia, but with a bilateral pyramidal tract sign. A study of her cerebrospinal fluid revealed albuminocytologic dissociation, and nerve conduction study revealed demyelination of her peripheral nerves. Moreover, electroencephalography findings were abnormal and anti-GQ1b antibody was positive. We diagnosed Fisher syndrome with Guillain-Barré syndrome and Bickerstaff brainstem encephalitis. We administered intravenous immunoglobulin treatment for 5 days and her symptoms gradually improved. However, her external ophthalmoplegia continued for several months.